Vestibular end organ injury induced by middle ear treatment with ferric chloride in rats

2016 ◽  
Vol 36 (2) ◽  
pp. 146-159 ◽  
Author(s):  
JH Lee ◽  
MS Kim ◽  
BR Park

Sensorineural hearing loss, ataxia, pyramidal signs, and vestibular deficits characterize superficial siderosis of the central nervous system. This study investigated changes in vestibular function, free radical formation, and phosphorylated cJun expression in the vestibular end organs after middle ear treatment with a ferric chloride (FeCl3) solution. A single injection of 70% FeCl3 solution into the unilateral middle ear cavity caused static vestibular symptoms, such as spontaneous nystagmus and head tilt. Asymmetric expression of c-Fos protein was observed in the bilateral vestibular nuclei and prepositus hypoglossal nuclei within 6 h after injection. Histopathologic examinations revealed partial hair cell loss, degeneration of the supporting stroma, and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells in the neuroepithelial layer of the crista ampullaris in FeCl3-treated animals. 5-(And-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate, acetyl ester and diaminofluorescein–2 diacetate fluorescence and immunoreactivity for nitrotyrosine increased markedly in the sensory neuroepithelial layer and nerve bundles of the crista ampullaris after 2 h. Strong immunoreactivity for phospho-cJun and cJun was observed in the type I hair cells of the crista ampullaris 120 h after injection. Thus, a single short-term treatment with a high concentration of FeCl3 in the unilateral middle ear cavity can induce activation of intracellular signals for cJun protein and oxidative stress through the formation of reactive oxygen species and nitric oxide in vestibular sensory receptors, resulting in vestibular dysfunction. These results suggest that activation of intracellular signals for cJun protein and oxidative stress may be a key component of the pathogenesis of vestibular deficits in patients with superficial siderosis.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Srinivas Sriramula ◽  
Nithya Mariappan ◽  
Elizabeth McILwain ◽  
Joseph Francis

Tumor necrosis factor-alpha (TNF-α) and angiotensin II (Ang II) play an important role in the pathophysiology of cardiovascular disease in part by inducing the cardiac hypertrophic response and oxidative stress. Recently we demonstrated that angiotensin induced hypertensive response is attenuated in mice lacking the gene for TNF-α. In this study, we examined whether Ang II induced cardiac hypertrophy and increased oxidative stress is mediated through TNF-α. Methods and results: Male TNF-α (−/−) and age matched control (WT) mice were subcutaneously implanted with osmotic minipumps containing Ang II (1 μg/kg/min) or saline for 14 days. Human recombinant TNF-α was injected in one group of TNF-α (−/−) mice (10 μg/kg/day) for 14 days. In WT+Ang mice, a temporal increase in blood pressure was observed during the study as measured by radio telemetry transmitters. At the end of the study, echocardiography revealed an increase in thickness and dimensions of left ventricle (LV) and decreased fractional shortening (%FS) in WT+Ang mice. Real time RT-PCR showed that Ang II- infusion resulted in an increase in heart/bodyweight ratio and of cardiac hypertrophy markers ANP and BNP, and profibrotic genes Collagen Type I, Collagen Type II, and TGF-β in WT mice. Electron Spin resonance spectroscopy revealed an increase in total ROS, superoxide and peroxynitrite in the WT+ANG mice when compared to control WT mice. However, these changes were all attenuated in TNF-α (−/−)+Ang mice. Ang II infusion also increased significantly the mRNA expression of gp91Phox, NOX-1, NOX-4 and AT1R in the LV of WT mice, but not in TNF-α (−/−) mice. Interestingly, injection of TNF-α in the TNF-α (−/−) mice, treated with Ang II resulted in increased cardiac hypertrophy and oxidative stress. Conclusions: Findings from the present study suggest that TNF-α plays an important role in the development of cardiac hypertrophy and oxidative stress in Ang II-induced hypertension.


2019 ◽  
Vol 9 (8) ◽  
pp. 197 ◽  
Author(s):  
Afonso S. I. Salgado ◽  
Juliana Stramosk ◽  
Daniela D. Ludtke ◽  
Ana C. C. Kuci ◽  
Daiana C. Salm ◽  
...  

Complex regional pain syndrome type I (CRPS-I) is a chronic painful condition. We investigated whether manual therapy (MT), in a chronic post-ischemia pain (CPIP) model, is capable of reducing pain behavior and oxidative stress. Male Swiss mice were subjected to ischemia-reperfusion (IR) to mimic CRPS-I. Animals received ankle joint mobilization 48h after the IR procedure, and response to mechanical stimuli was evaluated. For biochemical analyses, mitochondrial function as well as oxidative stress thiobarbituric acid reactive substances (TBARS), protein carbonyls, antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) levels were determined. IR induced mechanical hyperalgesia which was subsequently reduced by acute MT treatment. The concentrations of oxidative stress parameters were increased following IR with MT treatment preventing these increases in malondialdehyde (MDA) and carbonyls protein. IR diminished the levels of SOD and CAT activity and MT treatment prevented this decrease in CAT but not in SOD activity. IR also diminished mitochondrial complex activity, and MT treatment was ineffective in preventing this decrease. In conclusion, repeated sessions of MT resulted in antihyperalgesic effects mediated, at least partially, through the prevention of an increase of MDA and protein carbonyls levels and an improvement in the antioxidant defense system.


2016 ◽  
Vol 311 (6) ◽  
pp. R1192-R1199 ◽  
Author(s):  
Denise C. Cornelius ◽  
Lorena M. Amaral ◽  
Kedra Wallace ◽  
Nathan Campbell ◽  
Alexia J. Thomas ◽  
...  

Preeclampsia is associated with chronic inflammation and an imbalance among T-helper cell subtypes with an increase in T-helper 17 (TH17) cells. The objective of this study was to determine a role for TH17s, from the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia, in the etiology of hypertension and chronic inflammation during pregnancy. CD4+/CD25− T cells were isolated from rat spleens, cultured in TH17 media, and were verified as TH17s via flow cytometry. On day 12 of gestation, 1×106 TH17 cells from RUPP rats were adoptively transferred into NP rats, carotid catheters were inserted on day 18, and on day 19, mean arterial pressure (MAP) was recorded, serum and plasma were collected, and oxidative stress and production of agonistic autoantibodies to the ANG II type I receptor (AT1-AA) were analyzed. MAP increased from 100.3 ± 1.7 mmHg in normal pregnant (NP; n = 17) to 124.8 ± 2.1 mmHg in RUPP ( n = 22; P < 0.0001) and to 110.8 ± 2.8 mmHg in NP+RUPP TH17 ( n = 11). Pup weights in NP+RUPP TH17s were decreased to 1.92 ± 0.09 g from 2.39 ± 0.14 in NP rats ( P < 0.01). AT1-AA significantly increased from 0.1 ± 0.2 beats/min in NP to 15.6 ± 0.7 beats/min in NP+RUPP TH17s. IL-6 was 22.3 ± 5.7 pg/ml in NP and increased to 60.45 ± 13.8 pg/ml in RUPP ( P < 0.05) and 75.9 ± 6.8 pg/ml in NP+RUPP TH17 rats ( P < 0.01). Placental and renal oxidative stress were 238 ± 27.5 and 411 ± 129.9 relative light units·min−1·mg−1 in NP and 339 ± 104.6 and 833 ± 331.1 relative light units·min−1·mg−1 in NP+RUPP TH17, respectively. In conclusion, RUPP TH17 cells induced intrauterine growth restriction and increased blood pressure, AT1-AA, IL-6, and tissue oxidative stress when transferred to NP rats, indicating a role for autoimmune associated TH17 cells, to cause much of the pathophysiology associated with preeclampsia.


Author(s):  
Ramalingam ◽  
Santhanathas ◽  
Shaukat Ali ◽  
Zainalabidin

Prolonged exposure to nicotine accelerates onset and progression of renal diseases in habitual cigarette smokers. Exposure to nicotine, either via active or passive smoking is strongly shown to enhance renal oxidative stress and augment kidney failure in various animal models. In this study, we investigated the effects of resveratrol supplementation on nicotine-induced kidney injury and oxidative stress in a rat model. Male Sprague-Dawley rats were given nicotine (0.6 mg/kg, i.p.) alone or in combination with either resveratrol (8 mg/kg, i.p.), or angiotensin II type I receptor blocker, irbesartan (10 mg/kg, p.o.) for 28 days. Upon completion of treatment, kidneys were investigated for changes in structure, kidney injury markers and oxidative stress. Administration of nicotine alone for 28 days resulted in significant renal impairment as shown by marked increase in plasma creatinine, blood urea nitrogen (BUN) and oxidative stress. Co-administration with resveratrol however successfully attenuated these changes, with a concomitant increase in renal antioxidants such as glutathione similar to the conventionally used angiotensin II receptor blocker, irbesartan. These data altogether suggest that targeting renal oxidative stress with resveratrol could alleviate nicotine-induced renal injury. Antioxidants may be clinically important for management of renal function in habitual smokers.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Philipp Welschof ◽  
Matthias Oelze ◽  
Swenja Kröller-Schön ◽  
Thomas Jansen ◽  
Michael Hausding ◽  
...  

Objectives: In diabetes, cardiovascular complications are associated with endothelial dysfunction and oxidative stress. Empagliflozin (Empa), as a selective sodium-glucose co-transporter 2 inhibitor (SGLT2i) in clinical development, offers a promising novel approach for the treatment of type 2 diabetes by enhancing urinary glucose excretion. The aim of the present study was to test whether treatment with Empa could improve endothelial dysfunction in type I diabetic rats via reduction of glucotoxicity and associated oxidative stress. Research Design and Methods: Type I diabetes in Wistar rats was induced by an intravenous injection of streptozotocin (60 mg/kg). One week after injection Empa was administered via drinking water for 7 weeks. Results: Treatment with Empa (10 and 30 mg/kg/d), showed reduction of blood glucose and a normalization of endothelial dysfunction (aortic rings) in diabetic rats and a reduced oxidative stress in aortic vessels (dihydroethidine staining) and in blood (phorbol ester/zymosan A-stimulated chemiluminescence). Additionally, the pro-inflammatory phenotype and glucotoxicity in diabetic animals was normalized by SGLT2i therapy. Conclusion: In this study we could demonstrate that Empa improves hyperglycemia and prevents the development of endothelial dysfunction and oxidative stress in type 1 diabetic rats. Future studies will investigate the underlying mechanisms of these antioxidant and anti-inflammatory effects with special emphasis on low-grade inflammation, glucotoxicity and oxidative stress, all of which contributes to cardiovascular complications.


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